Many people get up in the morning and listen to the radio or watch television, unconcerned with how that sound and picture get to them. Some people are interested, but have a hard time understanding what they are told. Radio waves are part of the study of physics, so there are many mathematical formulas involved. It might be easier to understand if people took out the math and talked about the facts of radio waves.

Fact 1: The electromagnet spectrum covers all possible frequencies of electromagnetic radiation. This includes the visible light spectrum and microwaves, among other. Radio waves have the longest wavelengths, but they still travel at the speed of light. These wavelengths can be from 1 millimeter to 100 kilometers, measured from the peak of the wave to the following peak.

Fact 2: Lightning and meteors, or bodies out in space may cause radio waves. These can be picked up by receivers, and outer space radio waves are considered part of the background noise of the universe. These signals can interfere with each other, so artificial radio waves like television and radio have to be regulated to prevent overlap.  

Fact 3: Radio communication, radar, television, as well as some computer networks, navigations systems and cellular phones are considered artificially generated radio waves. The International Telecommunications Union works to divide the radio spectrum among users, differentiated by the frequency of the radio wave.

Fact 4: Frequencies are measured in units of Hertz, 1 hertz being equal to one wave crest per second. The energy of electromagnet waves is higher with the higher frequency, and higher energy results in shorter wavelengths. That is, electromagnet energy is directly proportional to frequency and inversely proportional to wavelength.

Fact 5: Specially built telescopes allow astronomers to detect the electro magnate radiation of bodies in space. Radio telescopes detect the sounds of the universe, and some look specifically for the sound of intelligent life.

Fact 6: The Very Large Array in New Mexico is made up of 27 receivers in a ‘˜y’ shape. This allows scientists to receive information from the large wavelengths of radio waves, and combine the data into meaningful information. The Parkes Radio Telescope was an earlier attempt to do the same thing through a single, 64 meter wide receiving dish, but the image was unsatisfactory.

Fact 7: Radio waves do carry sound, which is why radio wave receives were called ‘˜radios’. This becomes possible by modifying radio waves to carry the frequency. The audio frequency is adjusted to represent the sound of the transmission.

Fact 8: AM, or amplitude modulation, happens when the radio frequency waves and audio frequency are combined. This combination is then modulated, or adjusted to match the audio signal.

Fact 9: FM is frequency modulation of radio transmissions, which are less prone to background interference. In FM, the frequency of the combined amplitude and wavelength is adjusted.

Fact 10: The modern world has an abundance of artificial radio waves. It takes a significant amount of radio waves to harm living things, but that limit is being reached. Already people in occupations with a high exposure rate are being warned to watch for symptoms and take precautionary measures.